Changes of volatile components of tomato fruits during ripening

Volatile components obtained by simultaneous steam distillation-extraction from two varieties of tomato fruits at various ripening stages and their artificially ripened tomato fruits were analyzed by GC and GC-MS using a glass capillary column. One hundred and thirty compounds were identified. Of these, quantitative changes in the major thirty-six compounds were investigated. Hexanal, trans-2-hexenal, 2-iso-butylthiazole, 2-methyl-2-hepten-6-one, geranylacetone and farnesylacetone, which were estimated to be important volatile components of fresh tomato aroma by the GC-Sniff method, increased with natural and artificial ripening. However, many volatile components showed complicated changes in the case of artificially ripened tomato fruits.     

The isolation, properties, and enzymic breakdown of linamarin from cassava

A new method for the isolation of linamarin from Cassava is described. Using the pure glucoside, its properties and assay were investigated and a number of modifications to the previous assay procedure were introduced. The paper chromatography of the glucoside and means of detecting it on chromatograms are described. A procedure for preparing and assaying a crude preparation of linamarase is given. The variation in activity with pH, the stability of the enzyme, and its inhibition by buffers and by (1·5)-gluconolactone are described. A suggestion is made as to the role of linamarin and linamarase in the plant.     

Contribution of some volatile tomato components and their mixtures to fresh tomato aroma

Some volatile components of fresh tomatoes and mixtures of these components were evaluated for their contribution to fresh tomato aroma. cis-Hex-3-enal was the only individual component evaluated which was rated moderately similar to the aroma of fresh tomatoes. A mixture of cis-hex-3-enal, 2-methylhept-2-en-6-one, eugenol and β-ionone significantly improved the aroma of tomato juice prepared from foam-mat-dried tomato powder. Since the individual components of the mixture did not give significant improvement, the desired effect probably occurred as a result of a complex interaction among the added components and juice.     

The enzymic oxidative breakdown of linoleic acid in mushrooms (Psalliota bispora)

Summary A homogenate of the mushroomPsalliota bispora was incubated with (U-¹⁴C)linoleic acid. After extraction with ethyl ether and separation by thin-layer chromatography, two labelled products were detected. These were identified as 1-octen-3-ol and 10-oxo-trans-8-decenoic acid by GC, MS, IR and, additionally by derivatisation. During incubation both compounds were formed in a molar ratio of about 1:1.13-L(S)-hydroperoxy-cis-9,trans-11-octadecadienoic acid which has been suggested in the literature as the precursor of 1-octen-3-ol was reduced by the mushroom homogenate only to the corresponding 13-hydroxy fatty acid.

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Enzymatisch-oxidativer Abbau von Linolsäure in Champignons (Psalliota bispora)

Zusammenfassung Ein Homogenat aus Champignons (Psalliota bispora) wurde mit (U-¹⁴C)-Linolsäure inkubiert. Zwei markierte Produkte wurden in einem Ether-Extrakt nach dünnschichtchromatographischer Trennung gefunden. Sie wurden mittels GC-, MS-, IR-Spektroskopie und nach Derivatisierung als 1-Octen-3-ol und 10-Oxo-trans-8-decensäure identifiziert. Beide Verbindungen wurden bei der Inkubation im molaren Verhältnis von annähernd 1:1 gebildet. 13-L(S)-Hydroperoxy-cis-9,trans-11-octadecadiensäure, die in der Literatur als Vorläufer von 1-Octen-3-ol vermutet wird, wurde vom Pilz-Homogenat nur zur entsprechenden 13-Hydroxyfettsäure reduziert.

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Synonym withAgaricus bisporus     

Changes in the non-volatile organic acids of tomato fruit during ripening

A study has been made of the individual non-volatile organic acids in ethanolic extracts of tomato fruit during ripening. Whole fruit of three varieties and the outer walls and locular contents of one variety each at five stages of ripeness from mature green to full red were analysed. No trace of many of the K rebs-cycle acids could be detected. Maximum citric acid concentrations were found at either the green-yellow or yellow-orange stage of ripeness according to variety. Malic acid concentrations and the malic/citric acid ratio decreased progressively as the fruit ripened. Glutamic acid increased approximately ten-fold and aspartic acid more than doubled from the mature green to red stage of ripeness, but changes in pyrrolidonecarboxylic acid (PCA) during ripening were not statistically significant. In general, similar trends were observed in whole fruit and in the outer walls and locular contents, but malic, citric, glutamic and aspartic acid concentrations were higher in the locular contents than in the outer walls at all stages of ripeness. Alcohol-insoluble solids (AIS) decreased markedly between the green and green-yellow stages and then more slowly with further ripening.     

Effects of enzyme treatment on volatile and non-volatile compounds in dried green tea leaves

Food Science and Biotechnology - Green tea contains polyphenols, mainly four catechins, including (−)-epigallocatechin gallate, (−)-epicatechin gallate, (−)-epigallocatechin, and...     

A simple ion-exchange chromatographic determination of non-volatile organic acids in some Spanish exotic fruits

High-performance liquid chromatography (HPLC) permits accurate determination of non-volatile acids in fruit. The Spanish exotic fruits assayed were kiwi fruits (Actinidia chinensis), cvs Hayward, Bruno, Monty and Abbot; mangoes (Mangifera indica), cvs Smith and Lippens; papayas (Carica papaya), cv Solo; pineapples (Ananus comosus), cv Smooth Cayenne; and bananas (Musa cavendishii), cv Enana. Sample preparation for HPLC analysis basically consisted of methanol extraction, followed by an easy clean-up with a C18 cartridge. Separation of the different acids was accomplised using an ion-exchange column and detection was monitored at 214 nm. Reproducibility of the minor organic acids was quite acceptable, and the procedure described offers a rapid analytical alternative to gas chromatography. Oxalic, oxoglutaric, citric, galacturonic, tartaric, ascorbic,l-malic, quinic, succinic, fumaric andd-malic acids can be quantified by this method.

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Einfache Bestimmung von nicht-flüchtigen organischen Säuren in verschiedenen spanischen tropischen Früchten durch Ionenaustausch-Chromatographie

Zusammenfassung Die Ionenaustausch-Chromatographie wird als einfache Methode zur Bestimmung von nichtflüchtigen organischen Säuren in tropischen Früchten beschrieben. Die Proben waren Kiwis (Actinidia chinensis), cvs Hayward, Bruno, Monty und Abbot; Mangos (Mangifera indica), cvs Smith and Lippens; Papayas (Carica papaya), cv Solo; Ananas (Ananus comosus), Cv Smooth Cayenne; und Bananen (Musa cavendishii), cv Enana. Als Probenvorbereitung für die HPLC dienten eine Methanolextraktion und eine Reinigung mit C-18-Cartridges. Die verschiedenen Säuren wurden an einer Ionenaustauschsäule getrennt. Die Detektion erfolgte bei 214 nm. Die Methode ermöglicht die Quantifizierung von Ascorbinsäure, Citronensäure, Oxalsäure, Galakturonsäure, Oxoglutarsäure, Chinasäure, Traubensäure, Fumarsäure, Weinsäure,l-Apfelsäure undd-Apfelsäure.

     

Physical and mechanical properties of tomato fruits as related to robot’s harvesting

In order to better design, fabricate and control tomato harvesting robot, selected physical properties such as height, diameter, sphericity, surface area, volume, total mass, mass of pericarp and gelatinous matter, bulk density, density of pericarp and gelatinous matter, porosity, projected area, shape factor, and radius of curvature of two cultivar tomato fruits with different locule numbers were mainly investigated by image analysis and water displacement method. Mechanical properties such as friction and rolling resistance coefficients, and rupture energy, rupture force, compressibility, and loading slope of tomato fruits at two loading positions were determined by pull and loading test. Results showed the locule number had a significant effect (P < 0.05) on certain physical and mechanical parameters, such as height, diameter, surface area, rupture force, compressibility, and friction coefficient. The loading position also showed a significant effect (P < 0.05) on certain mechanical parameters, such as compressibility. The obtained properties are closely related to robot’s harvesting.     

红熟期番茄果实根霉果腐病与相关酶活性变化的研究

以"中蔬4号"红熟期番茄果实为材料,采用损伤接种的方法对番茄果实进行处理,测定其苯丙氨酸解胺酶(PAL)和几丁质酶(CHT)活性,研究这2种酶与番茄对根霉果腐病抗性的关系。结果表明,果腐根霉的侵染能够显著提高红熟期番茄果实PAL和CHT的活性,呈现出各自不同的变化趋势。     

Determination of carbofuran by GLC/NPD and HPLC in tomato fruits

Summary Two analytical methods, using GLC/NPD and HPLC to analyse carbofuran residues in tomatoes, are described. Both methods have shown a high recovery rate, up to 90%, and their detection limits are below the maximum residue limit set by Codex Alimentarius Mundi for carbofuran in tomatoes. Therefore, both methods may be of use in routine analysis of this pesticide in those fruits.

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Rückstandsanalyse von Carbofuran in Tomaten mit GLC/NPD und HPLC

Zusammenfassung Beschrieben werden zwei Arbeitsweisen zur Analyse von Rückständen des Methylcarbamat-Insecticids Carbofuran, die sich gut für routinemäßige Untersuchungen von Tomaten eignen. Die Wiederfin-dungsrate liegt über 90% und die Nachweisgrenze deutlich unter der Höchstmenge des Codex Alimentarius von 0,1 mg/kg.

     

Determination of carbofuran by GLC/NPD and HPLC in tomato fruits

Two analytical methods, using GLC/NPD and HPLC to analyse carbofuran residues in tomatoes, are described. Both methods have shown a high recovery rate, up to 90%, and their detection limits are below the maximum residue limit set by Codex Alimentarius Mundi for carbofuran in tomatoes. Therefore, both methods may be of use in routine analysis of this pesticide in those fruits.     

Effect of calcium and calmodulin antagonists on ethylene biosynthesis in tomato fruits

The aim of this work was to elucidate the mode of action of calcium in calcium-inhibited ethylene biosynthesis. In one experiment, mature green tomatoes were treated with 1·5% (w/v) CaCl₂+60 μM N-6(aminohexyl)-1-naphthalenesulphonamide (W5). 1·5% (w/v) CaCl₂+60 μM N-6(aminohexyl)-5-chloro-1-naphthalenesulphonamide (W7), 1·5% (w/v) CaCl₂ alone or distilled water (control). The control and the W7 treatment had much higher ethylene production than either the CaCl₂ treatment alone or the CaCl₂+W5 treatment. In another experiment, similar tomatoes were treated with 1·5% (w/v) CaCl₂+15 μM trifluoperazine (TFP). 1·5% (w/v) CaCl₂ only, or distilled water (control). The treatment with 1·5% CaCl₂+15 μM TFP gave higher ethylene production than 1·5% (w/v) CaCl₂ without TFP, and nearly the same level as the control towards the end of the experimental period. For enzyme and intermediate metabolite assays, mature green tomatoes were treated with 1·5% (w/v) CaCl₂ plus either W5 or W7. W5 treatment had a lower ethylene forming enzyme (EFE) activity, higher 1-aminocyclopropane-1-carboxylic acid (ACC) concentration, similar levels of ACC synthase activity and 1-(malonylamino)-cyclopropane-1-carboxylic acid concentration, compared to the control and W7 treatment. As W7 is a more potent calmodulin antagonist than W5, these results suggest a calcium-calmodulin inactivation of EFE activity. © 1998 SCI.     

Distribution of potassium,calcium and magnesium in strawberry fruits in relation to breakdown of the sulphited fruit

Methods are described for the determination of the free and bound Ca⁺⁺, Mg⁺⁺ and K⁺ in flesh and of these cations in achenes of strawberry fruits. A substantial amount of minerals was present in the achenes and the variation in mineral analyses of whole strawberries most probably reflects differences in the relative proportion of achenes to flesh. A negative correlation (r = ?0·8) was found between bound Ca⁺⁺ and the survival of fungal polygalacturonase in liquor of sulphited fruit. The possible rôle of calcium in reducing enzymic softening of sulphited strawberries is discussed.     

Environmental conditions in relation to stress in cherry tomato fruits in two experimental Mediterranean greenhouses

BACKGROUND: Considering the economic importance of tomato and its nutritional benefits to human health, a study was conducted on how different environmental factors (temperature, solar radiation and vapour pressure deficit (VPD)) influence hydrogen peroxide detoxification and several stress indicators in cherry tomato (Solanum lycopersicum cv. Naomi) fruits grown in two experimental Mediterranean greenhouses of parral (low‐technology) type and multispan (high‐technology) type. RESULTS: Three fruit samplings were made at the beginning, middle and end of the fruit production period. Values of temperature, solar radiation and VPD peaked at the third sampling in both greenhouses, being higher in the parral‐type greenhouse, while there was a reduction in market production at the third sampling. Peroxidation (malondialdehyde content and lipoxygenase activity) increased significantly at the third sampling, indicating the presence of oxidative stress caused by the rise in temperature, solar radiation and VPD. The ascorbate content, the activities of superoxide dismutase, catalase and ascorbate peroxidase and other stress indicators (proline and sucrose degradation) also increased at the third sampling. CONCLUSION: This study showed that conditions of higher environmental stress occurred at the third sampling and in the parral‐type greenhouse, leading to the accumulation of ascorbic acid in cherry tomato fruits and therefore to higher nutritional quality. Copyright © 2009 Society of Chemical Industry     

The odour of white bread III. Identification of volatile carbonyl compounds and fatty acids

Summary Carbonyl compounds of white bread, isolated by extraction, were identified as their 2,4-dinitrophenylhydrazones by thin-layer chromatography. Acids were separated from an extract of white bread as their sodium salts, regenerated and analysed by gas chromatography. 24 carbonyl compounds and 13 acids were identified. Of these, 9 carbonyl compounds and 8 acids had not been previously reported to occur in the aroma of white bread.

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Zusammenfassung Carbonylverbindungen von Weißbrot sind — nach Isolierung durch Extraktion — mittels Dünnschichtchromatographie als 2,4-Dinitrophenylhydrazone identifiziert worden. Sduren werden als Natriumsalze von einem Weißbrotextrakt abgetrennt und gaschro matographisch analysiert. 24 Carbonylverbindungen und 13 Säuren wurden identifiziert, wovon 9 Carbonylverbindungen und 8 Säuren in der einschlägigen Literatur noch nicht erwähnt worden sind.

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Die II. Mitteilung erscheint in Heft 5 (Anm. d. Red.)     

降低挥发性羰基化合物材料在卷烟滤嘴中的应用研究

为优化降低烟气中挥发性羰基化合物的功能材料(即降羰基物材料)在卷烟复合滤嘴中的应用工艺条件, 从功能材料添加量、滤嘴压降搭配、加料段长度等方面研究不同工艺条件对降羰基物材料的减害性能及其对卷烟感官质量的影响。结果表明, 当降羰基物材料在卷烟中的添加量为30 mg/支, 同时二元复合滤嘴为10 mm 加料段+15 mm 白段, 其中加料段压降为4000Pa/120 mm, 白段压降为2800 Pa/120 mm, 复合棒压降为2740 Pa/100 mm 时, 卷烟主流烟气中挥发性羰基物释放总量的选择性降低率达到32.3%, 且卷烟感官质量与对照卷烟相比无显著差异。